# Network Considerations

## Devin App ↔ Devin Server

First, make sure your computer can access your *Development Server.* The **Devin App** on your PC only ever connects to the **Devin Engine** on that server. In practice, this means that your *Development Server*'s firewall should allow incoming connections from your PC's IP address. 

### Default FileMaker Server Requirements

Both port `443` and `5003` are part of a default FileMaker Server installation. If you’re already hosting files through FileMaker Server, they’re almost certainly open and configured correctly—no extra network changes should be required to connect your Devin App to your *Development Server*.

<table><thead><tr><th width="83">Protocol</th><th width="66">Port</th><th>Purpose</th></tr></thead><tbody><tr><td>HTTPS</td><td>443</td><td>FileMaker Server API access</td></tr><tr><td>FMNET</td><td>5003</td><td>FileMaker Pro access to hosted <code>fmp12</code> files (Devin Engine)</td></tr></tbody></table>

{% hint style="info" %}
If you’ve enabled FileMaker’s HTTPS tunneling feature, all client traffic (including FMNet) is routed over HTTPS/443, so you no longer need to open port 5003.
{% endhint %}

## Devin Server ↔ Devin Server

All traffic to *Staging* or *Production* servers is routed through your *Development Server.* The **Devin App** never connects to them directly. In practice, this means that your *Staging* or *Production* servers must allow incoming connections from your *Development Server* (see table below).

### Environment-Specific Requirements

<table><thead><tr><th width="170">Scenario</th><th width="256">Development Server (Outbound)</th><th>Staging/Production Server (Inbound)</th></tr></thead><tbody><tr><td>Internet-Exposed</td><td>Allow HTTPS on TCP/443</td><td>Accept HTTPS on TCP/443 only from Development Server's IP</td></tr><tr><td>Internal (LAN/VPN)</td><td>Allow HTTPS on TCP/443</td><td>Permit HTTPS on TCP/443 per ACL</td></tr></tbody></table>

{% hint style="info" %}
&#x20;On the *Development Server*, the **Devin Engine** and **Devin Server API** communicate locally over `HTTP` on `localhost:45712` (configured automatically at install). When the *Development Server* reaches out to other Devin Servers, it uses `HTTPS` (default port `443`) through the same **IIS** or **Nginx** web server that FileMaker Server uses for Admin Console, WebDirect, and Admin/Data/OData APIs, leveraging your existing SSL certificate and reverse-proxy settings for end-to-end encryption.
{% endhint %}